High RPM Miss/Sputter

[douglee25]

Well I tried taking it up to 70mph or so in 3rd gear this morning and the did not stutter. Weird huh? With my luck, I fully expect the problem to surface again come summer time.

Doug

[M3Rob95]

try coils if it comes up again

[Julz69]

Put my new plugs in NGK iridiums the one with IX at the end. NO MORE MISFIRING car runs great now. I don't get that misfire anymore at 5600ish rpm in 3rd anymore. Man I wish I changed the plugs sooner.

[brando1118]

This may be a long shot, but I read through the entire thread before I posted so as not to be redundant. In the OP's first post he said he used anti-seize compound on the plugs. According to Pelican Part's Wayne, that is a no, no because of a possible arc from the plug to head facilitated by the anti-seize compound.
http://books.google.com/books?id=wJv...IPhPJDaMJiqBM8

God knows you've covered just about everything else that it could possibly be in the thread already.
Good luck.

[fatboycowen]

This may be a long shot, but I read through the entire thread before I posted so as not to be redundant. In the OP's first post he said he used anti-seize compound on the plugs. According to Pelican Part's Wayne, that is a no, no because of a possible arc from the plug to head facilitated by the anti-seize compound.
http://books.google.com/books?id=wJv...IPhPJDaMJiqBM8

God knows you've covered just about everything else that it could possibly be in the thread already.
Good luck.

Its not because of a possible arc from the plug, its because the plug needs to be grounded to the head, and the antisieze could prevent this grounding. Its right there in that link you put up.

[douglee25]

This may be a long shot, but I read through the entire thread before I posted so as not to be redundant. In the OP's first post he said he used anti-seize compound on the plugs. According to Pelican Part's Wayne, that is a no, no because of a possible arc from the plug to head facilitated by the anti-seize compound.
http://books.google.com/books?id=wJv...IPhPJDaMJiqBM8

God knows you've covered just about everything else that it could possibly be in the thread already.
Good luck.

Its not because of a possible arc from the plug, its because the plug needs to be grounded to the head, and the antisieze could prevent this grounding. Its right there in that link you put up.

Interesting. I would be perplexed as to how other vehicles I've owned specifically state to use antiseize on the plug threads. If it was indeed a grounding issue, how could other manufacturers get away with it?

Doug

[brando1118]

Thanks for that. Sorry to mislead. It was a lot of reading until I finally posted. I got lazy and assumed. Very dangerous.
Manufacturers can get a way with it because it's never a consistent problem with any particular make or model. It just happens "sometimes". But when you've got a thread like this where EVERYTHING seems to be addressed, it might be time to think outside the box for longshots. The anti-seize compound seems warranted enough, but it's still sketchy. But at this point what have you got to lose?

[fatboycowen]

Interesting. I would be perplexed as to how other vehicles I've owned specifically state to use antiseize on the plug threads. If it was indeed a grounding issue, how could other manufacturers get away with it?

Doug

If you think about it, when you torque the plugs in, there has to be metal to metal contact between the threads in some areas, so it should still ground. Maybe this is only a concern for high performance cars....

[douglee25]

Thanks for that. Sorry to mislead. It was a lot of reading until I finally posted. I got lazy and assumed. Very dangerous.
Manufacturers can get a way with it because it's never a consistent problem with any particular make or model. It just happens "sometimes". But when you've got a thread like this where EVERYTHING seems to be addressed, it might be time to think outside the box for longshots. The anti-seize compound seems warranted enough, but it's still sketchy. But at this point what have you got to lose?

Very true. I will keep it in the back of head next time I notice the problem.

Doug

[mbandit]

So, it seems like a couple people have fixed the problem for now by replacing the cam sensor. How much is the cam sensor and is it easy to replace? Other items that everyone seems to be doing is cleaning the MAF and replacing the fuel filter. My guess would be a weak coil if such a thing can happen. I get the same miss....(definatly feels ignition related) at high rpm and maybe only 2 to 3 actual missfires while running the car through 3rd and 4th floored.

[EstorilRoc3060]

^+1 and I'm having the same problem

[EstorilRoc3060]

Ok, so from my understanding, the choices we have to check the engine is...
-M50 mani leaks/tightness
-Cam Sensor (which I think might be my problem)
-O2 Sensor (another I might have)

Do you guys think that when I get my cams installed that it will get worse or go away, keep in mind I will be having Dr. Vanos install the cams with his "Sunbelt Vanos".

[douglee25]

Well had the car on the interstate today... the misfire is still there. I haven't seen the CEL but I may scan for codes when I'm back from business travel.

Lovely...

Doug

[Julz69]

you still have original coils?

[SpeedLi///Mit]

Nah, no way a pre-cat O2 sensor could do it. That WOULD definitely throw a code if it were getting bad enough of a reading to effect performance.

Odd thing is my car hasn't ALWAYS done it, just started about 10 months ago

damn that sucks man, I remember you posting up with probs when I was having misfire probs.

fwiw, the cam sensor in my buddies 97 M went out.. it would fail hot and the car wouldn't start, ran normally all rpm, just wouldn't restart untill it cooled down. It also set a fault code.

[douglee25]

you still have original coils?

Still the original coils but I did swap in brand new coil boots back in the summer along with new plugs. The cam sensor is also about 3-4 years old. The car has 106k on it. From what I've read, possible solutions are:

1. Coils
2. Coil Boots - Done
3. MAF Dirty
4. O2 Sensors
5. Cam Sensor - Done (4 years ago though)
6. Crank Sensor
7. Fuel Pump
8. Fuel Filter - Done
9. Plugs - Done

I'm not sure what to do next. My brother has a 330ci and I'm trying to find out the build date. Pre 9/2002 they have the same coils as the M3. I would like to try his out before I go throwing parts at the problem.

Doug

[CLEANM3whipz]

Subscribed

[mtmpow3r]

In this order.

Fuel Filter (most DIYers forget about it)
Seafoam that biach (use brakebooster line with 3/4 a bottle, and 1/4 in your gas, and go beat the hell out of her)
Clean MAF
Plugs (stay away from Platinum 4 plugs, go with single electrode copper ones)
O2 Sensors

[epj3]

Haha I hear ya, my car is nice and smooth all the other times, its just the one or two momentary "dips" in power up top before redline.

Oh well, one more reason to go with a standalone and turbo

Here's something interesting... still had this problem until Monday this week when I installed conforti software... Now it's completely gone and have not been able to reproduce the issue. Pulls smoothly to 7000 rpm.

[douglee25]

Here's something interesting... still had this problem until Monday this week when I installed conforti software... Now it's completely gone and have not been able to reproduce the issue. Pulls smoothly to 7000 rpm.

That's really weird?? What did that chip run you?

Doug

[mitchelrl]

I have the same problem as seen in my dynos...


I've been a lazy ass and haven't even attempted to fix it.

Do my bidding for me BFC!

For what it's worth, it did it on my stock tuning and dinan tuning.

Definitely more of an ignition problem.

I'm running the 2 pronged bosh iridium spark plugs as well.

[TheM3nsah]

8k!!! damn!!

[mitchelrl]

8k!!! damn!!

LOL!

No, 6500 RPMS. the time scale is just that, the time it took me from low RPM's to redline.
Notice the difference with the flywheel. (the pink run is my run without the flywheel.

[douglee25]

I have the same problem as seen in my dynos...


I've been a lazy ass and haven't even attempted to fix it.

Do my bidding for me BFC!

For what it's worth, it did it on my stock tuning and dinan tuning.

Definitely more of an ignition problem.

I'm running the 2 pronged bosh iridium spark plugs as well.

That's exactly where my engine is breaking up as well. Exact same spot! Weird. Sure seems ignition related to me. I found out this morning that my brother's 330ci has a build date of 2/2002, and therefore the coils will work in my car. I think we're going to attempt to swap these in and see if the problem is still present.

Doug

[epj3]

That's really weird?? What did that chip run you?

Doug

It's just a shark injector...